Hybrid Electric Vehicles (HEV's) may replenish electrical energy by using the internal combustion engine to operate a generator. The electricity produced by the generator may be stored in a battery. HEV systems can also recover kinetic energy by using the momentum of the vehicle to turn the generator. The electricity produced may be stored in the battery for subsequent use. Plug-in Hybrid Electric Vehicles (PHEVs) are an extension of existing HEV's with added energy flexibility. A PHEV may utilize a larger capacity battery pack than a standard HEV, and the PHEV has two initial sources of energy—fuel as well as electricity from the electric utility grid.
An objective of a HEV control system may be to minimize energy operational costs and emissions without compromising the vehicle drivability. Energy management control strategies may operate the HEV in electric drive mode in which the vehicle is operated with only the electric motor providing propulsion to maximize the battery power output. In a hybrid operation mode, the vehicle is propelled by both the engine and the electric motor. Advanced powertrain planning techniques may serve to enhance energy planning by maximizing the use of electric drive mode.
Similarly, conventional vehicles having an internal combustion engine as the sole means of propulsion rely on range prediction in order to provide drivers with accurate estimation of the distance available to be driven based on the fuel available at a given instant. Advanced planning techniques may enhance fuel consumption and enable a more accurate distance to empty calculation.